Research Article
Determination of Chlorpyrifos Residues in Organophosphate-Contaminated Soils from Selected Dairy Farms in Kilifi County, Kenya Using Liquid Chromatography-Mass Spectrometry (LC-MS/MS)
Atego Norbert Adum*,
Gicharu Gibson,
Carren Bosire,
Peter Makan
Issue:
Volume 14, Issue 3, September 2026
Pages:
36-44
Received:
13 June 2026
Accepted:
26 June 2026
Published:
17 July 2026
DOI:
10.11648/j.sjac.20261403.11
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Abstract: Organophosphate acaricides are widely used in livestock production to control ticks and tick-borne diseases, but frequent use of chlorpyrifos-based products may contaminate soils through residue accumulation. This study determined chlorpyrifos residues in soils from selected dairy farms in Kilifi County, Kenya. A cross-sectional survey was conducted among Forty four dairy farmers using questionnaires, interviews, and field observations to document acaricide brands, active ingredients, and application frequency. Farms were purposively selected based on reported use of chlorpyrifos-containing acaricides. Forty-four composite soil samples were collected from cattle spraying areas, drainage points, and nearby grazing sites in Kilifi South, Kaloleni and Kilifi North sub-counties. Samples were extracted and analyzed using liquid chromatography–mass spectrometry (LC-MS). Data were analyzed in GenStat using descriptive statistics and one-way ANOVA. Commonly used acaricides included Duodip, Tixfix, Vectoclor, Steladone, and Cynotrix. Most farmers applied acaricides twice weekly. Chlorpyrifos was detected in 24 of 44 samples, representing 54.5%. Mean concentrations differed among sub-counties, with Kilifi South recording the highest level at 18.903±0.114 ppb, followed by Kaloleni at 11.88±0.299 ppb and Kilifi North at 10.496±0.0447 ppb. The findings indicate soil contamination and support routine monitoring, farmer training, and stricter regulation of chlorpyrifos-based acaricides.
Abstract: Organophosphate acaricides are widely used in livestock production to control ticks and tick-borne diseases, but frequent use of chlorpyrifos-based products may contaminate soils through residue accumulation. This study determined chlorpyrifos residues in soils from selected dairy farms in Kilifi County, Kenya. A cross-sectional survey was conducte...
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Review Article
Role of Chemistry in Determining Time Since Death
Issue:
Volume 14, Issue 3, September 2026
Pages:
45-60
Received:
12 September 2026
Accepted:
4 October 2026
Published:
26 October 2026
Abstract: Accurate post‑mortem interval (PMI) estimation is fundamental to forensic science but traditional macroscopic indicators rapidly lose reliability. This review explains how chemical and molecular techniques are redefining PMI estimation. Early work focused on measuring electrolytes in vitreous humor (VH); the linear increase of potassium following cellular membrane breakdown remains a robust marker. Other metabolites such as creatinine, urea, glucose and hypoxanthine in VH, blood and synovial fluid extend the estimation window. Post‑mortem biochemical processes are also summarised, autolysis and putrefaction degrade macromolecules, produce volatile organic compounds and gases, and alter pH and redox potential, forming biochemical clocks. Biological matrices including VH, blood, cerebrospinal fluid, urine, muscle, liver and brain each provide different advantages and challenges. The review surveys tissues like muscle, liver and brain and describes how electrolyte leakage, metabolite accumulation and protein degradation offer complementary time markers. Key markers encompass electrolytes, metabolites, enzyme activities, protein degradation patterns, microRNAs and volatile organic compounds. Analytical tools such as gas/liquid chromatography, mass spectrometry, NMR spectroscopy and ion‑selective electrodes enable sensitive measurement. Emerging multi‑omics and spectroscopic techniques (ATR‑FTIR, Raman) integrated with machine‑learning models enhance resolution and show promise for multi‑organ metabolomics and proteomics. The review also notes limitations: environmental variability, inter‑individual differences, drugs and ethical constraints necessitate multidisciplinary approaches. Future research directions stress multi‑marker models, entomology integration, portable devices and population‑specific databases.
Abstract: Accurate post‑mortem interval (PMI) estimation is fundamental to forensic science but traditional macroscopic indicators rapidly lose reliability. This review explains how chemical and molecular techniques are redefining PMI estimation. Early work focused on measuring electrolytes in vitreous humor (VH); the linear increase of potassium following c...
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,
Muhammad Farhan Rashid
